ОСОБЛИВОСТІ СПЕКТРІВ ВИПРОМІНЮВАННЯ ВИХІДНИХ ТА ОПРОМІНЕНИХ ЕЛЕКТРОНАМИ УФ СД InGaN

Light-emitting diodes (LEDs) grown on the basis of InxGa1-xN solid solutions (x≤0.1) were investigated. It was found that the radiation spectrum of the studied samples at 300K consists of three bands with λ1max=370 nm (UV), λ2max=550 nm (yellow) and λ3max=770 nm (red). The first of them arises as a result of recombination transitions in quantum wells (QWs); the other two are of defective origin. The result of the temperature assessment of the pn-junction in the mode of the nominal operating current of the diode (I=20 mA) is close to 252℃. The drop in the efficiency of the LED radiation as a result of the increase in the current may be due to the increase in the relative contribution of non-radiative transitions when the quasi-Fermi level enters the region of the increased density of the tails of the zones. The doublet structure of the maximum of UV radiation – the band at 77K – is a consequence of the phonon repetition of the main emission line. Irradiation with electrons is accompanied by a drop in the intensity of the luminescence of all three bands; the occurrence of the maximum at λmax=420 nm is obviously related to the introduction of radiation defects into the QW region.